LXR linux/drivers/platform/chrome/cros_ec

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Sensor HUB driver that discovers sensors behind a ChromeOS Embedded
   4 * Controller.
   5 *
   6 * Copyright 2019 Google LLC
   7 */
   8
   9#include <linux/init.h>
  10#include <linux/device.h>
  11#include <linux/module.h>
  12#include <linux/platform_data/cros_ec_commands.h>
  13#include <linux/platform_data/cros_ec_proto.h>
  14#include <linux/platform_data/cros_ec_sensorhub.h>
  15#include <linux/platform_device.h>
  16#include <linux/slab.h>
  17#include <linux/types.h>
  18
  19#define DRV_NAME                "cros-ec-sensorhub"
  20
  21static void cros_ec_sensorhub_free_sensor(void *arg)
  22{
  23        struct platform_device *pdev = arg;
  24
  25        platform_device_unregister(pdev);
  26}
  27
  28static int cros_ec_sensorhub_allocate_sensor(struct device *parent,
  29                                             char *sensor_name,
  30                                             int sensor_num)
  31{
  32        struct cros_ec_sensor_platform sensor_platforms = {
  33                .sensor_num = sensor_num,
  34        };
  35        struct platform_device *pdev;
  36
  37        pdev = platform_device_register_data(parent, sensor_name,
  38                                             PLATFORM_DEVID_AUTO,
  39                                             &sensor_platforms,
  40                                             sizeof(sensor_platforms));
  41        if (IS_ERR(pdev))
  42                return PTR_ERR(pdev);
  43
  44        return devm_add_action_or_reset(parent,
  45                                        cros_ec_sensorhub_free_sensor,
  46                                        pdev);
  47}
  48
  49static int cros_ec_sensorhub_register(struct device *dev,
  50                                      struct cros_ec_sensorhub *sensorhub)
  51{
  52        int sensor_type[MOTIONSENSE_TYPE_MAX] = { 0 };
  53        struct cros_ec_command *msg = sensorhub->msg;
  54        struct cros_ec_dev *ec = sensorhub->ec;
  55        int ret, i;
  56        char *name;
  57
  58
  59        msg->version = 1;
  60        msg->insize = sizeof(struct ec_response_motion_sense);
  61        msg->outsize = sizeof(struct ec_params_motion_sense);
  62
  63        for (i = 0; i < sensorhub->sensor_num; i++) {
  64                sensorhub->params->cmd = MOTIONSENSE_CMD_INFO;
  65                sensorhub->params->info.sensor_num = i;
  66
  67                ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
  68                if (ret < 0) {
  69                        dev_warn(dev, "no info for EC sensor %d : %d/%d\n",
  70                                 i, ret, msg->result);
  71                        continue;
  72                }
  73
  74                switch (sensorhub->resp->info.type) {
  75                case MOTIONSENSE_TYPE_ACCEL:
  76                        name = "cros-ec-accel";
  77                        break;
  78                case MOTIONSENSE_TYPE_BARO:
  79                        name = "cros-ec-baro";
  80                        break;
  81                case MOTIONSENSE_TYPE_GYRO:
  82                        name = "cros-ec-gyro";
  83                        break;
  84                case MOTIONSENSE_TYPE_MAG:
  85                        name = "cros-ec-mag";
  86                        break;
  87                case MOTIONSENSE_TYPE_PROX:
  88                        name = "cros-ec-prox";
  89                        break;
  90                case MOTIONSENSE_TYPE_LIGHT:
  91                        name = "cros-ec-light";
  92                        break;
  93                case MOTIONSENSE_TYPE_ACTIVITY:
  94                        name = "cros-ec-activity";
  95                        break;
  96                default:
  97                        dev_warn(dev, "unknown type %d\n",
  98                                 sensorhub->resp->info.type);
  99                        continue;
 100                }
 101
 102                ret = cros_ec_sensorhub_allocate_sensor(dev, name, i);
 103                if (ret)
 104                        return ret;
 105
 106                sensor_type[sensorhub->resp->info.type]++;
 107        }
 108
 109        if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
 110                ec->has_kb_wake_angle = true;
 111
 112        if (cros_ec_check_features(ec,
 113                                   EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
 114                ret = cros_ec_sensorhub_allocate_sensor(dev,
 115                                                        "cros-ec-lid-angle",
 116                                                        0);
 117                if (ret)
 118                        return ret;
 119        }
 120
 121        return 0;
 122}
 123
 124static int cros_ec_sensorhub_probe(struct platform_device *pdev)
 125{
 126        struct device *dev = &pdev->dev;
 127        struct cros_ec_dev *ec = dev_get_drvdata(dev->parent);
 128        struct cros_ec_sensorhub *data;
 129        struct cros_ec_command *msg;
 130        int ret, i, sensor_num;
 131
 132        msg = devm_kzalloc(dev, sizeof(struct cros_ec_command) +
 133                           max((u16)sizeof(struct ec_params_motion_sense),
 134                               ec->ec_dev->max_response), GFP_KERNEL);
 135        if (!msg)
 136                return -ENOMEM;
 137
 138        msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
 139
 140        data = devm_kzalloc(dev, sizeof(struct cros_ec_sensorhub), GFP_KERNEL);
 141        if (!data)
 142                return -ENOMEM;
 143
 144        mutex_init(&data->cmd_lock);
 145
 146        data->dev = dev;
 147        data->ec = ec;
 148        data->msg = msg;
 149        data->params = (struct ec_params_motion_sense *)msg->data;
 150        data->resp = (struct ec_response_motion_sense *)msg->data;
 151
 152        dev_set_drvdata(dev, data);
 153
 154        /* Check whether this EC is a sensor hub. */
 155        if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) {
 156                sensor_num = cros_ec_get_sensor_count(ec);
 157                if (sensor_num < 0) {
 158                        dev_err(dev,
 159                                "Unable to retrieve sensor information (err:%d)\n",
 160                                sensor_num);
 161                        return sensor_num;
 162                }
 163                if (sensor_num == 0) {
 164                        dev_err(dev, "Zero sensors reported.\n");
 165                        return -EINVAL;
 166                }
 167                data->sensor_num = sensor_num;
 168
 169                /*
 170                 * Prepare the ring handler before enumering the
 171                 * sensors.
 172                 */
 173                if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 174                        ret = cros_ec_sensorhub_ring_allocate(data);
 175                        if (ret)
 176                                return ret;
 177                }
 178
 179                /* Enumerate the sensors.*/
 180                ret = cros_ec_sensorhub_register(dev, data);
 181                if (ret)
 182                        return ret;
 183
 184                /*
 185                 * When the EC does not have a FIFO, the sensors will query
 186                 * their data themselves via sysfs or a software trigger.
 187                 */
 188                if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 189                        ret = cros_ec_sensorhub_ring_add(data);
 190                        if (ret)
 191                                return ret;
 192                        /*
 193                         * The msg and its data is not under the control of the
 194                         * ring handler.
 195                         */
 196                        return devm_add_action_or_reset(dev,
 197                                        cros_ec_sensorhub_ring_remove,
 198                                        data);
 199                }
 200
 201        } else {
 202                /*
 203                 * If the device has sensors but does not claim to
 204                 * be a sensor hub, we are in legacy mode.
 205                 */
 206                data->sensor_num = 2;
 207                for (i = 0; i < data->sensor_num; i++) {
 208                        ret = cros_ec_sensorhub_allocate_sensor(dev,
 209                                                "cros-ec-accel-legacy", i);
 210                        if (ret)
 211                                return ret;
 212                }
 213        }
 214
 215
 216        return 0;
 217}
 218
 219#ifdef CONFIG_PM_SLEEP
 220/*
 221 * When the EC is suspending, we must stop sending interrupt,
 222 * we may use the same interrupt line for waking up the device.
 223 * Tell the EC to stop sending non-interrupt event on the iio ring.
 224 */
 225static int cros_ec_sensorhub_suspend(struct device *dev)
 226{
 227        struct platform_device *pdev = to_platform_device(dev);
 228        struct cros_ec_sensorhub *sensorhub = platform_get_drvdata(pdev);
 229        struct cros_ec_dev *ec = sensorhub->ec;
 230
 231        if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
 232                return cros_ec_sensorhub_ring_fifo_enable(sensorhub, false);
 233        return 0;
 234}
 235
 236static int cros_ec_sensorhub_resume(struct device *dev)
 237{
 238        struct platform_device *pdev = to_platform_device(dev);
 239        struct cros_ec_sensorhub *sensorhub = platform_get_drvdata(pdev);
 240        struct cros_ec_dev *ec = sensorhub->ec;
 241
 242        if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
 243                return cros_ec_sensorhub_ring_fifo_enable(sensorhub, true);
 244        return 0;
 245}
 246#endif
 247
 248static SIMPLE_DEV_PM_OPS(cros_ec_sensorhub_pm_ops,
 249                cros_ec_sensorhub_suspend,
 250                cros_ec_sensorhub_resume);
 251
 252static struct platform_driver cros_ec_sensorhub_driver = {
 253        .driver = {
 254                .name = DRV_NAME,
 255                .pm = &cros_ec_sensorhub_pm_ops,
 256        },
 257        .probe = cros_ec_sensorhub_probe,
 258};
 259
 260module_platform_driver(cros_ec_sensorhub_driver);
 261
 262MODULE_ALIAS("platform:" DRV_NAME);
 263MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
 264MODULE_DESCRIPTION("ChromeOS EC MEMS Sensor Hub Driver");
 265MODULE_LICENSE("GPL");
 266